Extensible insoles



June 2, 1970 P. STAPLETON 3,

EXTENSIBLE INSOLES Filed Sept. 26, 1967 z Sheets-Sheet 1 [III/6n f0!"RzfcrLSzapZe on By his Attorne June 2,1970 P. L. STAPLETON 3,

- EXTENSIBLE INSOLES Filed Sent. 26, 19s? a Sheets- 811991; 2

United States Patent 3,514,880 EXTENSIBLE INSOLES Peter L. Stapleton,Leicester, England, assignor to USM Corporation, Fiemington, N.J., acorporation of New Jersey Filed Sept. 26, 1967, Ser. No. 670,598 Int.Cl. A43b 1 3/ 88 US. Cl. 36-44 2 Claims ABSTRACT OF THE DISCLOSURE Anovel insole comprising discrete forepart and heel portions joined by anextensible portion, the forepart and heel portions each having locatingholes therein to facilitate positioning of the insole on the last.Preferably, the forepart and heel portions are joined by means ofextensible material such as polyurethane foam interposed betweenoverlapped margins of the two portions.

This invention relates to a novel shoe insole.

In the interest of good shoemaking it is desirabe, when attaching a shoeinsole to the last, that both the toe and heel portions of the insoleare correctly positioned with respect to the bottom of the last. Whenusing tacks to attach an insole to a last it is a usual practice toposition the toe and attach the toe portion of the insole beforeproceeding to the heel portion. Unless the insole has been madeaccurately to fit the last bottom an undesirable overlap between edgeportions of the last and insole can occur.

One of the various objects of the present invention is to provide aninsole which facilitates accurate positioning of toe and heel portionsof the insole on the bottom of a last.

The invention provides, in accordance with one of its several features,a shoe insole comprising a forepart portion having a locating holetherein joined in overlapped relationship with a heel portion having alocating hole therein by means of material interposed between overlappedmargins of said portions, the interposed material being extensible toallow relative movement between the forepart and heel portions tofacilitate positioning of the insole against the bottom of a last.

There is hereinafter described an insole illustrative of certainfeatures of this invention having extensible material in the form of astrip of polyurethane foam between overlapping margains of a flexibletoe and forepart portion and a more rigid heel and waist portion.Insoles embodying the invention are made shorter lengthwise than thestandard insole and are extended, through the provision of theextensible polyurethane foam portion, accurately to fit the bottom of alast at its toe and heel ends. While the insole hereinafter describedincludes a flexible toe and forepart portion it could include a flexibleheel and waist portion joined in overlapped re lationship with a morerigid toe portion without departing from the scope of the invention. Theinsole is provided with locating holes at the toe and heel portions tofacilitate practice of the method of this invention.

The above and other features of this invention will now be moreparticularly described with reference to the accompanying drawings andpointed out in the claims.

It is to be understood that the particular embodiments I referred toabove and hereinafter described are delineated for illustration of theinvention only and are not to be construed as limiting the scopethereof.

In the drawings:

FIG. 1 is a view of the bottom of an insole embodying certain aspects ofthe invention;

sole 10 is temporarily supported in position against'the FIG. 2 is aside view of the insole illustrated in FIG. 1 and attached to a last;

FIG. 3 is a plan view of a second illustrative insole; and

FIG. 4 is a plan view of a third illustrative insole.

The illustrative insole shown in FIGS. 1 and 2, referred to generally bythe reference number 10, comprises a toe and forepart portion 12 made ofconventional flexible insoling material. A more rigid heel and waistportion 14 has a leading edge face 16 (FIG. 2) skived to provide anunderlay portion of a lap joint for joining the portions 12 and 14. Theinsole is moulded to accommodate the bottom contours of the last. Theportion 12 has a scarfed face 20. The portions 12 and 14 have locationholes 28 and 30 therein for use in locating the insole on a last, ashereinafter described.

Interposed in the lap joint is a piece of extensible joining material 18made of suitable-density polyurethane foam and joined by means ofsuitable adhesive to the face 16 and to the scarf face 20 (FIG. 2) ofthe forepart portion 12. Thus the flexible portion of the insole isjoined to the more rigid portion through the intermediary of thematerial 18.

The insole 10 is cut from a prepared composite sheet from which aplurality of insoles can be cut. To provide the composite sheet a stripof the joining material 18 is adhered to a longitudinal margin of astrip of material which provides the heel and waist portion 14 of theinsole, said margin is skived to provide the face 16 and coated withadhesive for securing the material 18 thereto. The strip of joiningmaterial 18 has a width similar to the Width of the face 16. A strip ofmaterial which provides the flexible toe and forepart portion 12 of theinsole is skived along one edge to provide the scarf face 20. This face20 has a width similar to the width of the joining material and iscoated with adhesive and applied to a face of the material 18 oppositeto its face adhered to the face 16. The three layers are pressedtogether to form a composite sheet for use in making a plurality ofinsoles having flexible toe and forepart portions and more rigid heeland waist portions joined in overlapped relationship by means of anextensible material. The insoles are out about a half size undersizewith respect to the lengths of the lasts with which they are to beassembled (i.e. about one sixth of an inch) for a purpose herein afterexplained.

The polyurethane foam joining material 18, aswell as being compressibleand thus avoiding unnecessary thickess in the insole in a finished shoe,is extensible in directions of shear of the joining material. Thisextensibility permits limited relative movement between the insoleportions 12 and 14, both in lengthwise and widthcrepancy in the lie ofthe toe and forepart portion 12 with respect to the bottom of the lastcan be corrected by moving the portion 12 relative to the portion 14.

An insole of the construction just described is attached to a last bymeans other than tacks which have the disadvantage that they have to beremoved at a later stage in the manufacture of a shoe. The way in whichthe inbottom of a last 22 (FIG. 2) will now be described.

The last 22 is provided with a pair of location projections in the formof pins, 24 and 26 respectively, which project outwardly from the bottomof the last. The pin 24 is positioned a predetermined distance from theheel end of the last and the pin 26 is positioned a' predeterm ined'distance from the toe end of the last. Two location holes 28 and 30(FIG. 1), of a size to fit the pins, are punched respectively in theportions 14 and 12 of the insole. The

hole 28 is positioned in the insole in relation to the heel end thereofat a position in the heel portion corresponding to the position occupiedby the pin 24 in relation to the corresponding portion of the lastbottom and the hole 30 is positioned in the insole in relation to thetoe end thereof at a position in the toe portion corresponding to theposition occupied by the pin 26 in relation to the corresponding portionof the last bottom and irrespective of the position of the hole 28.

The portion 14 of the insole is positioned on the bottom of the last 22by locating the pin 24 in the hole 28. In the interests of accuracy andto provide an adequate attachment of the insole to the last the pin 24is a push-fit in the hole 28. As hereinbefore mentioned, the insole iscut undersize in length and the insole is extended by moving the portion12 relatively to the portion 14 so that the pin 26 can be inserted inthe hole 30. Since the toe ends of the last and insole respectively arethe datum points for positioning the pin 26 and hole the toe end of theinsole is positioned correctly in alignment with the toe end of thelast.

The polyurethane foam joining material 18 has an elastic characteristicsuch that the extended insole positioned on the last by the pins 24 and26 tends to contract so that the insole is gripped on the pins whichattach it to the last and retain it against the bottom of the last. Thepin 26 has a recess 32 which helps to retain the insole in position.

So that the shoe can be readily removed from the last at a later stagein manufacture the pin 26 is chamfered to provide a sloping face 34. Inremoving the shoe from its last the back of the shoe is urged off thebackpart of the last, the insole being lifted off the pin 24, and theshoe is then moved toewardly of the last, the insole being carried awayfrom the last by the sloping face 34. The sloping face 34 makes itunlikely that the portion 12 of the insole will bind on the pin 26.

In a modification of the insole just described the joining material 18is less in width than width of the face 16 and the scarf face 20. Thefaces 16 and 20 are completely coated with adhesive so that when theinsole is supported in position on a last bottom the faces 16 and 20 arepressed together (compressing the polyurethane foam), portions thereofcoming together rigidly to secure the portions 12 and 14 of the insolein overlapped relationship.

Instead of comprising a flexible toe and forepart portion and a morerigid heel and waist portion an insole may comprise a flexible forepartportion, and more rigid toe and heel and waist portions. In such aninsole the flexible forepart portion is joined to the more rigid toeportion by a lap joint. If desired joining material 18 may be sandwichedin said lap joint instead of the lap joint joining the flexible portionto the heel and waist portion.

FIG. 3 shows a second insole embodying further features of thisinvention which facilitate use of the above described method comprisinga flexible forepart portion joined in overlapped relationship with amore rigid heel and waist portion 42 and a more rigid toe portion 44.

Location holes 46 and 48 correspond respectively with the holes 28 and30 to locate the insole on a last having locations pins similar to thepins 24 and 26. The forepart portion 40 provides an extensible portion,being rigidly secured in overlapped relationship with the portions 42and 44 by means of adhesive. The heel and waist portion 42 is skived toform an underlay 50 and the toe portion is skived to forman underlay 52.To enable the forepart portion 40 to be extended to facilitatepositioning of the insole on the last bottom a plurality of relativelyshort slashes 54 are made extending across the forepart portion. Theslashes 54 extend completely through the substance of the forepartmaterial so that lengthwise stressing of the insole causes the slashesto gap and thus effect extension of the forepart portion of the insole.

A third illustrative insole 60 shown in FIG. 4 is similar to the insoleshown in FIG. 3 in that a forepart portion 62 is made extensible bybeing slashed completely through the substance of the forepart material.However, in this case a single slash 64 only is made extending acrossmost of the width of the forepart portion. Holes 66 extending throughthe insole 60 at either end of the slash 64 minimize the likelihood ofthe slash running out to the opposite side edges of the insole. Acovering in the form of a piece of readily compressible and extensiblepolyurethane foam 68 is stuck over the slash 64 on the top surface ofthe insole, i.e. the surface nearest to the foot in the finished shoe,to avoid the likelihood of discomfort or trapping of the foot of thewearer of the finished shoe.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent 0f the United States is:

1. A shoe insole comprising a forepart portion joined in overlappedrelationship with a heel portion by means of an extensible strip ofpolyurethane foam material interposed between overlapped margins of saidportions to allow relative movement between the forepart and heelportions to facilitate positioning of the insole against the bottom of alast.

2. A shoe insole comprising a toe portion joined with a heel portion bymeans of an extensible portion comprising a forepart portion of theinsole having a single slash extending across most of the forepartportion between two holes made through the forepart portion, and whereinthe slash extends completely through the substance of the forepartmaterial, a location hole in the heel portion and a location hole in thetoe portion, said location holes being adapted to receive respectivelylocation projections provided on heel and toe portions of a last bottomto support the insole in position against the last bottom, the locationholes being respectively positioned in said portions of the insole atpositions corresponding to the positions occupied by the projections inrelation to the corresponding portions of the last bottom.

References Cited UNITED STATES PATENTS 2,346,27 9 4/ 44 Stritter 36-442,809,450 10/57 Stritter 36-44 2,185,993 1/40 Haskell 12-442. 2,211,5098/40 Lumbard 36-43 3,144,669 8/64 Lamy.

PATRICK D. LAWSON, Primary Examiner US. Cl. X.R l 142

